This invention relates generally to telephone handsets, and has to do particularly with the acoustical path along which sound reaches the microphone.
For optimum sound reproduction, telephone handsets incorporate a somewhat complex acoustic path along which sound reaches the microphone, the path requiring complex geometries in the portions of the handset adjacent the microphone.
Generally, it is an aim of one aspect of this invention to incorporate the complex acoustic path geometry mentioned above into a simple, integral gasket, thus not requiring a plurality of pieces and components to have critical shapes.
More particularly, this invention provides a complex acoustic path for bringing sound to a microphone, the path comprising:
aperture means,
a pre-plenum adapted to receive sound through said aperture means,
an acoustic filter communicating with the pre-plenum and defining relatively small openings for sound to exit the pre-plenum,
a voice tube extending away from said filter and adapted to receive sound from the filter, the voice tube terminating in a microphone plenum adjacent the microphone.
Furthermore, this invention provides a gasket for bringing sound from an aperture means to a microphone, the gasket defining a pre-plenum adapted to receive sound through said aperture means, an acoustic filter communicating with the pre-plenum and defining relatively small openings for sound to exit the pre-plenum, and a voice tube extending away from said filter and adapted to receive sound from the filter, the voice tube terminating in a microphone plenum adjacent the microphone.
Finally, this invention provides a method of delivering sound to a microphone, comprising the steps of:
admitting the sound to a pre-plenum,
passing the sound from the pre-plenum through an acoustic filter defining relatively small openings for sound to exit the pre-plenum,
receiving the sound at one end of a voice tube communicating with and extending away from said filter,
passing the sound to the other end of the voice tube and there admitting the sound to a microphone plenum disposed adjacent the microphone.